Appliance for holding films for dental radiographs



T. B. S. WALLACE.

APPLIANCE FOR HOLDlNG FILMS FOR DENTAL RADIOGRAPHS.

APPLICATION FILED FEB.24,1920.

Lggpgjyb Patentefi N01 29, 1921.

1 FNVENTOR I THOMAS B. 5. WALLAcE APIELLMWCIJ HGLDIICIG- FILIE'IS F03, DENTAL EVADIGGEAYHS.

Specification of Letters itatent.

Patented Nov. 29 @921.

.enplieation filed Kiebruary 2 1920. Serial No. 360,891.

Z (LE whom it may concern:

Be it known thatLTinonas B. S. WAL- LACE, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement in Appliances for Holding Films for Dental Radiographs, of which the following is a specification...

My invention has reference to an appliance for mounting or holding a sensitized film whereby it may be conveniently positioned in the mouth of a patient for making dental radiograms.

As is well known, the film employed. in dental iii-ray photography relatively small in size (approximately 33x42 millimeters), and is inclosed in a waterproof and lightproof package that is slightly flexible so as to accommodate itself in the mouth of the person being photographed. Considerable difficulty has always been experienced in conveniently handling the film in the persons mouth as few facilities have been prorided to assist in this portion of the X-ray operation. Also there is an uncertainty as to the exact plane in which the film is placed in the persons mouth so that the rays oft-the apparatus, instead of passing directly to the film on an axis at right angles or substantially right angles to the plane of the film, are not infrequently at a decided acute or obtuse angle thereby giving a distorted or foreshortened image which 15 so incorrect and inaccurate that mistakes and errors are liable to and often do occur which are really no fault of the operator. Therefore, I have devised a structure overcomes to a great extent these inherent difiiculties whereby true, or substantially true radiographs are made possible and at the same time the subject may hold the in position with certainty, ease and comparative comfort.

In designing my appliance for holding film of this character, l have several objects in mind, viz:the provision of a structure that is simple in construction, light in weight and not cumbersome; that is easy to handle in assembling the film package therewith; that has facilities for ready use by the person being photogr plied, and is dependable when in use; can be manufactured cheaply so that it may be sold for a moderate price; will indicate proper position for the Crookes tube, and is made of separable parts so that it is capable of being easily taken apart and i prefer to carry out the divers objects of my invention 1n substantially the manner hereinafter fully described and as more particularly pointed out in the claims, ref

erence being now had to the accompanying drawings that form a] part of this specification, in which Figure 1 is a vertical end edge elevation of my appliance assembled with a film package, and illustrating the manner of using it upon the teeth of the lower jaw. v

Fig. 2 is a. central vertical section thereof.

Fig. 3 is a perspective View of the two clamping parts separated and in position ready for assembly.

Fig. l'is a detail View of the structure for determining the approximate or compensated axis upon which the rays of the lrookes tube are projected to the film.

Fig. 5 is a diagrammatic View showing the manner of use for focusing the X-ray tube.

These members I prefer to make of sheet I metal of a suitable gage so that they will retain their shape and yet be suificiently yielding to permit the interlocking or coacting parts to readily be assembled. The holder member preferably, comprises a back or main portion 5 of substantially rectangular shape from the lower edge whereof projects an outwardly and slightly upwardly curved lug 6 forming a finger piece and a pair of longitudinally disposed )arallcl slots 7, 7, are made in the body of the plate extending from near the opposite end edge of the plate comprising the holder member to and past the center thereof.

Intermediate the end edges the plate forming member A. is looped laterally at a right angle to itself to provide a horizontally disposed shelf 8 that is adapted when the appliance is in use to be placed upon the top 01? crown of-the teeth it is desired to repro duce by radiograph. The loop just mentioned is not an angular one, and I prefer to extend 1t, beginning at the ends of slots 7 Hereinafter more fully appear.

maining large plece of the plate between the slots and opposite the portion from i which rib 10 is formed is turned downber.

' three parts,

channel 9, as seen in Fig.1. the plate intermediate the slot provides a :yielding finger 18 extending upwardly in when the parts are wardly between said slots toward the rear of back 5 providing a yielding lip 11 the curvature whereof is a substantial continuation of the curve forming the channel or socket 9, and itslower edgeextends inwardly toward back 5, as seen in Fig. 2 of the drawin s.

The 'lockin member B that cooperates with the ho der member, just described, comprises a metal plate forming a body 12 ofysubstantially the same general dimensions as back '5, and edge has an outward and slightly upwardly curved lug 13 providing a finger piece that corresponds with lug 6 on the holder member and is disposed below and closely adjacent the latter when the (parts are assembled. This body 12 is provied with vertical parallel slots 14, 14 that extend downwardly from its upper edge. a suitable distance; said slots being disposed upon said body 12 in substantially the same planes thereon as slots 7 are positioned upon the holder mem- These slots 14 divide the plate into the two outer parts forming spring fingers 15, 15 that are bent at 16, or about midway their wardly toward back 5 of the holder member, and at their upper portions are again bentin the-same direction at the places 17 so as to fit into the adjacentlower portions of the The part of the same plane as said plate, but its upper portion is bent in a curve 19 oppositely to ,the .upper portions of fingers 15, but cou forming substantially; to the curvature of lip 11 with which it is adapted to register in cooperation- In assembling a film package 20 with the hereinbefore described 'coacting memjbe'rs',

I the package-is placed with itsupper edge in channel 9 and against lip-11 of holder A with the back of the package toward the rear of thebaclc member 5. The locking member B is then held ill-the position shown in Fig. 3 and fingers 15 and 18 thereof are inserted between the package 20 and back member 5 of the holder. The locking member B is forced inwardly until the lugs or its lower longitudinal.

tang 25 on'one of t height, obliquely out-' fin er pieces 6 and 13 come together during which movement upper deflected portions of the yielding fingers 15 will have snappedinto channel 9 to lock the parts against separation and the upper edge portion of the film pack 20 will be securely clamped. between the spring lip 11' and the upper curved portion 19 of finger 18, as seen in Figs. 1 and 2 of the drawings.

When the film package and holding appliance have been placed in the .mouth of a subject, it is inconvenient and sometimes difficult for the o erator to ascertain in which position the -ray apparatus'should be placed inorder to accurately reproduce the parts it is desired to photograph, and forthe purpose of assisting in determining an approximate or compensated axis for the rays, 1 have provided my appliance with an adjustable and removable indicator device.

detachably assemble with portions of the holder member A and .to project longitudh nally therefrom out of the mouth of the subject. The attaching end of bar 21 is preferably widened, as at 22, and provided with a longitudinally disposed slot 23 the function whereof is to receive the upstanding rib 10 of the shelf when the end portion of bar 21 is placed u )on the top of the shelf between the longitudinal edge thereof and the rib. A downwardly and backturned tang 24 is provided upon the edge of the widened portion 22 of the bar to fit around the adjacent end edge and a portion of the under side of shelf '8; Also to further assist in retaining bar 21 on the shelf, 1 have rovided a downwardl and transversely 3611i,

lie longitudinal edges of the bar that is adapted to fit around the ad acent side or longitudinal edge'of the shelf and engage the underside thereof in substantially the same manner as tang 24 is employed on the end edge of the shelf. To

permit the reversal of the structure when the appliance is used upon the opposite side of the personsmouth, I have placed tangs 24 and 25 adjacent and corresponding with tangs 24 and 25, just' described, except that the former tangs are bent back toward the other surface of bar 21, as seen in the drawings, so that the bar need only be turned over or reversed to permit its use on the opposite side of the mouth.

This bar, when mounted upon the shelf, isin a lane parallelwith the horizontalaxis of the film package and upon the outer end of the bar I mount a pointer 26 to be adjusted to the plane in which the film is found to be positioned. .A small threaded stud 27 projects from the bar 21, and upon this stud is carried 'pointer'26, a movable indicator 28-and a compensator 29 that are free to be rotated on the stud and which may be secured in any adjustable position by a lock, nut 30 screwedonto the end of stud 27. l

W hen the structure is in use it is placed in the persons mouth (the lower jaw teeth are indicated herein) the shelf resting upon the crown of the teeth with the film package onthe lingual side and facing outwardly toward the teeth and is retained in this position by the pressure of thepersons linger on lug 6. The operator then observes the plane or tilt of the film package and adjusts pointer 26 to a plane that will touch the upper and lower edges of the bent package which will be in a plane'simil'ar to the plane shown in the drawings, he then sets indicat01- 28 parallel to the long axis of the tooth. Then by bisecting the angle formed the pointer and the indicator with the compensator the parts are clamped together. The, compensator plane is now the nearest or-approximate plane in which a nearly true .radiograph may be made, because the averag plane of the bent package having been de ermined by pointer 26 and the compensator plane being at a right angle thereto, a minimum convergence or distortion is possible in the finished radiograph. New, by adjusting the indicators or gages of the X-ray instrument so thatwhen focused by the operator they will register with bar 21 and compensator 29, the operator can determine the axis for the rays from the tube and thereby locate his X-ray apparatus, as shown diagrammatically in Fig. 5 of the drawings.

It is obvious from the foregoing that modifications of the precise structure shown may be made, and I desire it understood there fore that such changes/are contemplated as capable of being made Without departing from the scope of the appended claims.

What I claim as new is 1. [a holder for film packs for dental EL a5 ray photography comprising separable cooperating mei'nbers provided with spring elements adapted to engage a film peel: and having-elements for positioning the holder with reference to the teeth and for manually holding said structure in desired positions.

2. A holder for film packs for dental X- ray photography comprising coiiperating members adapted to engage a film pack and having elements for positioning the same with reference to the teeth and for 1nanu ally holding said structure in desired positions, and'detacliable means coacting with =said holder and rovided with adjustable film paelr'in the mouth and the direction for positioning the source of the rays.

A lilni holding appliance for X-ray pho o raphy comprising a plate bent interrned its ends to provide a channel with elements for ind1c'ating the plane of the members extended from the edges thereof at substantially right angles to each other, said plate being slotted transversely of said channel to form a tongue, a second plate slotted to provide a plurality of fingers adapted to cocperate respectively with the channel and tongue or" said first-mentioned plate for securing the edge of a film pack Within said channel.

4:. A film-holding appliance comprising a plate bentintermediate its ends to provide members extended at substantially right angles to each other, a tongue extended from one of said members, and a second plate having a finger cooperating respectively with said tongue whereby the film pack is secured in position by said plates. I

5. A film holding appliance comprising a plate bent intermediate its ends to provide a channel adapted to receive the edge or" a film paclr and providing angularly disposed members upon opposite sides of said chana plurality of indicators adjustably secured to the opposite end of said bar.- 7

H v v 1. A gfillll-llOlfilll'lg appliance for .X-ray photography comprising a. plate bent intermediate its endsto provide a channel with members extended from the'edges thereel at substantially right angles to each other;

said plate being slotted transversely of said channel to form a tongue, asecond plate slotted to provide a plurality of fingers adapted to coiiperate respectively with the channel and tongue of said first-mentioned plate for securing the edge of aiilin paclr:

within said channel, and handle members extended. from said plates which inte. t when said plates are assembled. j

8. A film holding appliance comprising a plate bent to provide a body member and shell projecting laterally therefrom, longi tudinal rib projecting from the upper stir face of said shelf, a second plate having members coacting with said first-mentioned plate whereby a film pack is held between said plates, a bar having a slotted end portion cooperable with said shelf and rib, and an indicator upon. theopposite end of said bar.

9. it. film holding appliance comprising a plate bent to provide a body member and a shelf projecting laterally therefrom, a longi of. said shelf, a yielding tongue on said body member, a second plate having a tongue coacting with the first-mentioned tongue whereby a film pack is held between said plates, a bar having a slotted portion engageable with said rib, tangs on'the adjacent portion of said bar and coactable with said shelf, and a plurality of adjustable elements upon the opposite end of said bar.

10. A film holding appliance comprising a plate bent to provide members disposed at v I substantially right angles and provided with plurality of indicators adjustably secured to the opposite end of said bar.

filgnecl at Chicago, county of Cook and State of Illinois, this 20th day of February 1920.

THOMAS B. S. WALLACE. Witnesses:

. P. J. HARMON, F. A. CLARKE. 

